Merge pull request #3 from parrt/master

pulling in fixes

CHANGES.txt

@@ -1,5 +1,9 @@
 ANTLR v4 Honey Badger early access
 
+Jan 30, 2012
+
+* Moving to github.
+
 Jan 28, 2012
 
 * ~[] stuff is allowed and works inside sets etc...

README.txt

@@ -0,0 +1,9 @@
+ANTLR v4 early access
+
+Terence Parr, parrt at cs usfca edu
+ANTLR project lead and supreme dictator for life
+University of San Francisco
+
+INTRODUCTION
+
+Coming soon...

tool/playground/E.g

@@ -1,3 +1,82 @@
-lexer grammar E;
-I : ~[ab] ~[cd]* {System.out.println("I");} ;
-WS : [ \n\u000D]+ -> skip ;
+/** Simple statically-typed programming language with methods and variables
+ *  taken from "Language Implementation Patterns" book.
+ */
+grammar E;
+
+// START: file
+file:   (methodDecl | varDecl)+ ;
+// END: file
+
+// START: var
+varDecl
+    :   type ID ('=' expr)? ';'
+    ;
+type:   'float' | 'int' | 'void' ; // user-defined types
+// END: var
+
+// START: method
+methodDecl
+    :   type ID '(' formalParameters? ')' block // "void f(int x) {...}"
+    ;
+
+formalParameters
+    :   type ID (',' type ID)*
+    ;
+// END: method
+
+// START: stat
+block:  '{' stat* '}' ;   // possibly empty statement block
+
+stat:   block
+    |   varDecl
+    |   'if' expr 'then' stat ('else' stat)?
+    |   'return' expr? ';' 
+    |   expr '=' expr ';' // assignment
+    |   expr ';'          // func call
+    ;
+// END: stat
+
+/* expr below becomes the following non-left recursive rule:
+expr[int _p]
+    :   ( '-' expr[6]
+        | '!' expr[5]
+        | ID
+        | INT
+        | '(' expr ')'
+        )
+        ( {8 >= $_p}? '*' expr[9]
+        | {7 >= $_p}? ('+'|'-') expr[8]
+        | {4 >= $_p}? '==' expr[5]
+        | {10 >= $_p}? '[' expr ']'
+        | {9 >= $_p}? '(' exprList? ')'
+        )*
+    ;
+*/
+
+// START: expr
+expr:   expr '[' expr ']'       // array index like a[i], a[i][j]
+    |   expr '(' exprList? ')'  // func call like f(), f(x), f(1,2)
+    |   expr '*' expr
+    |   expr ('+'|'-') expr
+    |   '-' expr                // unary minus
+    |   '!' expr                // boolean not
+    |   expr '==' expr          // equality comparison (lowest priority op)
+    |   ID                      // variable reference
+    |   INT
+    |   '(' expr ')' 
+    ;
+
+exprList : expr (',' expr)* ;   // arg list
+// END: expr
+
+ID  :   LETTER (LETTER | [0-9])* ;
+fragment
+LETTER : [a-zA-Z] ;
+
+INT :   [0-9]+ ;
+
+WS  :   [ \t\n\r]+ -> skip ;
+
+SL_COMMENT
+    :   '//' .* '\n' -> skip
+    ;

tool/src/org/antlr/v4/automata/LexerATNFactory.java

@@ -237,6 +237,7 @@ public class LexerATNFactory extends ParserATNFactory {
 				int x = c;
 				int y = chars.charAt(i+2);
 				if ( x<=y ) set.add(x,y);
+				i+=2;
 			}
 			else {
 				set.add(c);

tool/src/org/antlr/v4/parse/ANTLRLexer.g

@@ -119,12 +119,7 @@ package org.antlr.v4.parse;
 
 
 @members {
-    public Token prevToken;
-    @Override
-    public void emit(Token token) {
-        super.emit(token);
-        if ( token.getChannel()==Token.DEFAULT_CHANNEL ) prevToken = token;
-    }
+    public boolean isLexer = false;
 }
 
 // --------
@@ -227,10 +222,10 @@ COMMENT
 
 ARG_OR_CHARSET
 options {k=1;}
-    :   {prevToken.getType()!=RULE_REF}?=> LEXER_CHAR_SET {$type=LEXER_CHAR_SET;}
-    |   {prevToken.getType()==RULE_REF}?=> ARG_ACTION     {$type=ARG_ACTION;}
+    :   {isLexer}?=> LEXER_CHAR_SET {$type=LEXER_CHAR_SET;}
+    |   {!isLexer}?=> ARG_ACTION    {$type=ARG_ACTION;}
     ;
-    
+
 fragment
 LEXER_CHAR_SET
     :   '[' ('\\]'|'\\'|~('\\'|']'))* ']'
@@ -412,7 +407,7 @@ TOKENS_SPEC  : 'tokens'  WSNLCHARS* '{'  ;
 
 IMPORT       : 'import'               ;
 FRAGMENT     : 'fragment'             ;
-LEXER        : 'lexer'                ;
+LEXER        : 'lexer'     {isLexer=true;} ;
 PARSER       : 'parser'               ;
 GRAMMAR      : 'grammar'              ;
 PROTECTED    : 'protected'            ;